1. Field of the Invention
The present invention relates to a circuit component supplying system which supplies circuit components ("CCs") to a target device such as a CC mounting device, a feeder which is suitable for the CC supplying system, and a method of managing supplying of CCs, and particularly to the art of facilitating the management of supplying of CCs or improving the reliability of the CC-supply management.
2. Related Art Statement
There is known an CC supplying system which supplies CCs to a target device such as a CC mounting device. One example of this system is disclosed in Japanese Patent Application laid open for opposition under Publication No. 7-101793. The disclosed system includes (1) a sort of CCs which are accommodated in a CC accommodating member to which an identification mark of the sort of CCs is adhered; (2) a feeder which supports the CC accommodating member in which the CCs are stored, and which supplies the CCs and has a memory for storing the number of CCs remaining therein; (3) a reader which reads the identification mark of the sort of CCs from the CC accommodating member; (4) a writing and reading device which writes data on, and reads data, from the memory of the feeder; (5) a stock data base which stores the respective identification codes of the sorts of CCs which are not in use in a current CC mounting operation, and the respective numbers of remaining CCs of those sorts, such that each identification code is related to the number of remaining CCs of a corresponding sort and such that those data can be changed; and (6) a CC-data processing device which reads, while taking into account the identification mark read by the reader, data from one of the memory of the feeder and the stock data base and writes the data on the other. When the CC-data processing device reads data from, or writes data on, the memory of the feeder, it utilizes the above writing and reading device.
This CC supplying system utilizes the stock data base for managing the respective numbers of remaining CCs of all sorts, in the following procedures. Before a CC mounting operation is started, the respective identification codes of all sorts of CCs, the respective names of all the sorts, and the respective numbers of remaining CCs of all the sorts are stored in the stock data base such that each code is related to a corresponding CC name and a corresponding remaining-CC number.
(1) A CC accommodating member in which a sort of CCs are accommodated is set on a feeder, and the identification code (i.e., bar code) adhered to the CC accommodating member is read by a reader (i.e., bar-code reader).
(2) The CC name and the remaining-CC number corresponding to the identification code read in Procedure (1) are read from the stock data base, and are written on the memory of the feeder by the writing and reading device. To this end, the feeder is equipped with a communication section which transmits data to, and receives data from, the writing and reading device.
Thus, each feeder holds the data about the sort of CCs set therein.
(3) Each feeder is set at a predetermined position in a supply section of a CC mounting device.
(4) The CC mounting device judges, according to given information, whether each feeder has been set at the predetermined position, based on the CC name stored in the memory of the feeder. The Japanese document states that if an error has been found with the setting of the feeder, the CC mounting operation is not started before an operator re-sets the feeder to the correct position.
Thus, a preparing operation before a CC mounting operation finishes. In Procedure (4), the CC mounting device reads the data from the memory of the feeder set thereon, and this reading is carried out via a communication section of the CC mounting device and the communication section of the feeder.
A CC mounting operation is carried out as follows:
(5) each time the feeder supplies one CC, the remaining-CC number stored in the memory of the feeder is decremented by one.
(6) The CC mounting device periodically monitors the remaining-CC number which is decremented one by one in Procedure (5), calculates, taking into account a time needed for mounting all CCs on each circuit substrate and a number of CCs of each sort mounted on each circuit substrate, a time when each feeder becomes empty, and controls a display device to indicate the calculated time. Based on the time displayed, an operator changes the feeder with a new one, as needed. The new feeder should be one which has been subjected to Procedures (1) and (2).
The CC mounting operation is followed by the following procedure:
(7) The data stored in the memory of each feeder are read out by the writing and reading device reads, and used for updating the data stored in the stock data base. In this way, the stock data base is utilized for managing the respective numbers of remaining CCs of all the sorts of CCs that are not in use in any CC mounting operations.
As is understood from the foregoing description, the supplying of CCs can be managed with ease and reliability, by assigning respective identification codes to different sorts of CCs. However, it is preferred that the management of supplying of CCs be much easier.
Meanwhile, in Procedure (4), the CC mounting device (strictly, the control section thereof) cannot judge whether each feeder has been set at the correct position, if it cannot identify the position on the supply section where each feeder has actually been set. However, the Japanese document does not disclose how the CC mounting device can identify the position. If the CC mounting device is equipped with a plurality of communication sections corresponding to a plurality of feeder holding portions of the supply section, respectively, and each of the communication sections is connected to the control section, independent of the other communication sections, the control section would identify one of the communication sections of the supply section which has exchanged information with the communication section of each feeder, and thereby identify the position where each feeder has been set on the supply section. However, there are some cases where it is impossible, or not desirable, that each of a plurality of communication sections be connected to a control section, independent of the other communication sections. It is a general practice to employ, for minimizing the number of wire cables, a communication network in which a plurality of communication sections are parallel connected to a control section. However, if each of a plurality of communication sections is connected to a control section, independent of the other communication sections, the above-indicated common communication network could not be employed, which would lead to increasing the production cost of the CC supplying system as a whole.